Hyperglucagonemia and hyperkinetic circulation after portocaval shunt in the rat.

The study was aimed at investigating whether increased portal venous inflow (PVI) after portocaval shunt (PCS) in the rat is the result of selective splanchnic vasodilatation or whether it is part of a generalized circulatory disturbance. Rats with PCS (n = 9) and sham-operated controls (n = 8) were studied 2 wk after surgery by measuring cardiac output (CO), PVI, and hepatic artery flow (HAF) with radioactive microspheres. Plasma glucagon (GL) was measured by radioimmunoassay. PCS rats had increased CO (46.2 +/- 2.8 vs. 28.2 +/- 1.7 ml X min-1 X 100 g-1, P less than 0.001) and reduced arterial pressure and total peripheral resistance. PVI was markedly increased (7.7 +/- 0.7 vs. 4.3 +/- 0.2 ml X min-1 X 100 g-1, P less than 0.001), but this appeared to be part of a generalized circulatory disturbance, since when PVI is expressed as percent of CO no difference is observed between PCS and sham-operated rats (17.0 +/- 1.5 vs. 15.8 +/- 1.3%, NS), indicating the absence of a preferential splanchnic vasodilatation. GL increased after PCS (548 +/- 130 vs. 156 +/- 23 pg/ml, P less than 0.005), and significant correlations were observed between GL and CO (r = 0.787, P less than 0.001) and between GL and PVI (r = 0.806, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)